Association between undiagnosed hypertension and microalbuminuria in South Asians without known diabetes.

Data suggest increased rates of chronic kidney disease (CKD) in those with undiagnosed hypertension (HTN). Our study aimed to determine the prevalence of CKD in undiagnosed hypertensives in a previously unreported subgroup of individuals of South Asian ethnicity. We analysed data from subjects in the ADDITION-Leicester study, a UK based multiethnic, community diabetes screening study. Standard definitions included: HTN-mean recorded BP of ⩾140/90 mm Hg, CKD stage 3 and above-estimated glomerular filtration rate (eGFR) <60 ml min(-1) per 1.73 m2 and microalbuminuria as albumin creatinine ratio ⩾3 mg mmol(-1). Logistic regression was performed with age, gender and body mass index (kg m(-2)) as co-variates. 6082 individuals (52.5% female, mean age, 57.2 years; White European, 77.8% and South Asian, 22.0%), 31.1% had undiagnosed HTN. Overall, individuals with undiagnosed HTN compared with normotensives had an odds ratio for microalbuminuria of 2.24 (95% confidence interval (CI): 1.72-2.94). For South Asians, the odds ratio was 3.81. (95% CI: 2.24-6.47) for microalbuminuria with a trend towards an eGFR<60 ml min(-1) per 1.73 m2. Future studies should consider intensified screening for HTN to refine the population suitable for CKD screening, particularly in the South Asian ethnic group.

High frequency polarization modulation method for measuring birefringence.

A high frequency modulation method utilizing a photoelastic polarization modulator for the measurement of optical birefringence is described and discussed. Although the apparatus has the high sensitivity required to measure very small retardations, the accurate measurement of larger retardations is emphasized and a particularly simple null detection technique for such measurements is described. Results obtained for some common uniaxial crystals are presented and compared with previously obtained results.

High frequency polarization modulation method for measuring optical rotation.

A high frequency photoelastic modulator is used to measure optical rotation. Its application for rotations of different orders of magnitude is described and assessed. The method has high sensitivity and permits rapid, accurate, and continuous measurements. Illustrative results are given for crystals having either natural or magnetically induced optical activity.